Experimental Design Diagrams

My Research Question: Will the location on my plot effect the pH of the soil?

My Prediction: If I change the location on my plot, then the pH will be effected           because different types of soil have different pHs.

Controlled variables are: The same amount of soil, same equipment used to test the soil, the soil is the same depth down from the surface, soil is stored in the same individual plastic bags and the water used to test pH is from the same source.

For my experiment, I’ll need pH testing strips, 3 dirt samples from each different location, distilled water, plastic bags to hold the dirt, a rolling pin to crush the soil, a screen to filter it, a spot plate, and duplex indicator.

Procedure: I'll go out to the plot and find dirt about 6 inches from the top and get rid of any large rocks and anything on top that's not dirt. Next, I'll put the dirt into plastic bags and leave them open so that the soil dries out. I'll label the bags with the location. When the soil is dry, I'll remove it from the bag and sort out the rocks and pieces of grass, etc., and crush the soil with a rolling pin. Next, I'll put the soil through a screen. When I'm done, the soil will be put back into the plastic bag and then I can do the pH test. Once I have the spot plate, I can put some soil in the large well. Then, I can add duplex indicator until the soil is wet and let it sit for a minute. After a minute, I'll tilt the spot plate until some of the indicator goes into the smaller well. Then, I'll match the color of the indicator to a color on the color chart to find the pH. I'll do this three times and take the average and put it in the final column of the table.